A chaotic nine-minute spell shortly before half time saw Argentina under-20s fall to a first defeat of the Sudamericano as Uruguay ran out comfortable 3-0 winners in a rain soaked Quito.
The two sides played out an entertaining 3-3 draw when they met in the first group stage but despite making improvements on Monday evening, Los Pibes were unable to claim even a point.
Claudio Úbeda’s side were looking the more likely to breakthrough with leading scorer Marcelo Torres already having gone close but the momentum shifted just after the half hour mark when Tomás Belmonte was shown a red card for a late challenge on Rodrigo Bentancur.
Having barely threatened but with a numerical advantage, Uruguay seized the initiative and within minutes were ahead when the impressive Nicolás De La Cruz fired La Celeste ahead from 30 yards.
Argentina needed to get to half time but two minutes later Los Pibes found themselves further behind when Mathías Olivera slipped in behind the static defence to slot the ball past Ramiro Macagno.
Try as they might, Argentina were unable to find a way back after the break and when Rodrigo Amaral nodded in a third on the hour mark, the contest was over.
Colombia are up next for Argentina on Thursday evening and a win will be required to get World Cup qualification back on track.